A man has been arrested after allegedly making racist remarks on Twitter relating to critically ill footballer Fabrice Muamba.

The 21-year-old man from Pontypridd, south Wales, was arrested on Sunday.

Muamba, 23, is fighting for his life in hospital after suffering a heart attack and collapsing during an FA Cup tie.

The Bolton Wanderers midfielder fell to the ground during the live televised match against Tottenham Hotspur at the London team's White Hart Lane ground.

Thousands of wellwishers have expressed their sympathy since the incident during Saturday's early evening match.

A steady stream of fans visited Wanderers' Reebok Stadium to place flowers, shirts and other tributes at the ground.

Thousands more left messages of support on a series of Get Well Soon Fabrice Muamba tribute pages on Facebook.

South Wales police confirmed the arrest of a man for allegedly making "racially offensive" comments on Twitter.

Officers did not confirm that Muamba was the target of the remarks.

However, police forces throughout the UK regularly take action against those who post racially offensive remarks on Twitter but rarely feel the need to issue a public statement indicating it has happened.

The statement said: "South Wales police have arrested a 21-year-old male from the Pontypridd area in connection with racially offensive comments made on the social network site Twitter. The male is currently being held in custody at Swansea Central police station."